CVE-2023-4921
A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.40%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue(). We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.40% probability · 33th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel · debian/debian linux
- Source
- cve-coordination@google.com
References
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8fc134fee27f2263988ae38920bc03da416b03d8Exploit, Mailing List, Patch, Vendor Advisory
- https://kernel.dance/8fc134fee27f2263988ae38920bc03da416b03d8Exploit, Patch, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.htmlMailing List, Third Party Advisory
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8fc134fee27f2263988ae38920bc03da416b03d8Exploit, Mailing List, Patch, Vendor Advisory
- https://kernel.dance/8fc134fee27f2263988ae38920bc03da416b03d8Exploit, Patch, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.htmlMailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.